Usually, a compact disc player is a machine which is applied to read digital signals recorded in a compact disc and to transform these signals into audio or video signals by means of an optical signal pick up lens. If the signal pick up lens gets dirty, its reading function may deteriorate and subsequently the audio or video signals transformed may become defective.
Unforturnately, the signal pick up lens is located inside the compact disc player so that it is inconvenient for the operator to clean dirt from the lens.